Effect of Ba Filling Fraction on Thermoelectric Properties of p-type Ba_yFe_(1.6)Co_(2.4)Sb_(12)

摘要

Effect of Ba filling fraction on the thermoelectric properties of p-type filled skutterudite compounds Ba_yFe_(1.6)Co_(2.4)Sb_(12) (y = 0-0.63) were investigated. Ba_yFe_(1.6)Co_(2.4)Sb_(12) showed p-type conduction. The hall coefficient (R_H) and seebeck coefficient (alpha) increased with increasing Ba filling fraction. But hole concentration (p) and electrical conductivity (sigma) decreased. While Ba filling fraction was about 0.4, the lattice thermal conductivity (kappa_L) reached the minimum value. The results show that effect of Ba rattling on phonon scattering is the strongest as Sb-icosahedron partial voids are filled by Ba. A maximum dimensionless thermoelectric figure o merit (ZT) value of 0.7 was obtained for Ba_(0.38)Fe_(1.6)Co_(2.4)Sb_(12) at 750 K.